Underfeed stoker



April 17, 1928.

A. F. SCHWENDNER UNDERFEED STOKER Filed Dec. 5, 1924 s Sheets-Shet 1 ITNESSE I ATTORNEY April 17,1928.

A. F. SCHWENDNER UNDERFEED STOKER Filed Dec. 5. 1924 3 Sheets-Sheet 2 r Al? .Scbwendner jlTNESSES' INVENTOR I W BY ATTORNEY I Patented Apr. 17, 1928.

UNITED- STATES PATENTCOFFICE.

ANTHONY I. SCHWEND'NER, OF ESSINGTON, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYII- VANIA.

UN DER'EEED STOKER.

Application filed December 3, 1924. Serial No. 753,555.

My invention relates to under-feed stokers and especially to that type of stoker havin one or more secondary rams driven throug suitable mechanism from the main ram.

An object of my invention is to produce a mechanism which will transmit motion from one reciprocating or oscillating mem her to another and which will permit of a change in the amplitude of movement of the second or driven member without interrupting the operation of the device.

A further object of my invention is to produce a device in which the amplitude of movement of the driven member may be varied at any phase of the cycle of operation without requiring an undue force.

A still further object of my invention is to provide an apparatus of the character designated which shall be simple, relatively light, inexpensive, easy of assembl and disassembly, yet rugged and free rom danger of failure of any kind.

These and other objects of my invention will be manifest from the accompanying description, having reference to the accompanying drawings in which Fig. 1, is a verti cal section taken through the center line of a retort of an under-feed stoker illustrating one embodiment of my device; Fig. 2 is a section on line IIII of Fig. 1; Fig. 3 is a perspective view of a pair of connecting links taken from the side opposite to that from which Fig. 1 is taken; Fig. 4 is a front view of the actuating mechanism of my device; Fig. 5 is a perspective view of the operatin cam and selector arm of my device; an Fig. 6 is a vertical sectional view of the selector arm and operating cam.

In Fig. 1,'I show a portion of an under-' feed stoken 14 of conventional type. In this stoker fuel from a-hopper 10 falls by gravity into a ram box 12 from which it isdischarged into-a retort 22 by the rearward motion of a ram 11 which is actuated by any driving means, these driving means being well known and hence not illustrated. In

the retort is a deflector plate 15 and the reoperating arm 19 by a pin 21 extendingthrough the branches 28 of said arm. The

operating arm is pivoted at its lower extrem- I if desirable. This ram is operated by a rod 23 which engages a forked collar 24, in turn pivotally connected to .the secondary ram 26 by a pin 25. The rod 23 is driven from the operating arm 19 by a variable stroke mechanism which I shall now describe.

On the end of the rod 23 opposite to the collar 24 is a collar 32 which is flattened at the end and extends beyond the extremity of the rod 23. The collar 32 is provided with a hole 34 to receive a pin 35. The pin 35 also supports connecting links 37 and is in turn supported by blocks 38 and 39 enga 'ng slots 41 in the bracket 13. Suitable was ers 42 and pins 43 hold the blocks 38 and 39," the connecting links 3737 and the collar 32 in fixedposition on the pin 35. The connecting links 37 which are more clearly shown in Fig. 3 are provided with holes 4444 to receive the pin 35. At one end of each of the connecting links 37 is a counter-weight 46 which may be of any convenient shape but should be narrow enough to fit between the sides of the bracket 13 and should be spaced far enough apart to clear the connecting rod 23. Should this not provide sufficient weight to counter-balance. the weight and give definite upward movement to the opposite portions 47 with respect to the hole 44 as a pivot, the counter-weights may be extended outwardly as at 48 at their extremities. If desired the links 37 may each be increased in thickness around the hole 44 thus forming an enlarged boss 51 and giving increased bearing surface. i

In the end 47 of each of the links 37 is an irregular shaped opening 52 comprising a bottom horizontally extending surface 53, an inclined surface 54 and an upper stepped surface 55. It should be noted that the stepped surface 55 is slightly under-cut as at 56 for the purpose hereinafter to be described. The upper corner is chamfered at 58 to engage a limit arm to be described hereinafter.

The operating arm 19 is provided with a vice for no movement the counter-weight46 pulls the end 47 upwardly, causing the pin 61 to engage the bottom surface portion 53' is provided with a series of notches 63 on its side adjacent the connecting link. The selector arm is pivotally mounted on a shaft 65 in the bracket 13. A counter-weight 67 tends to force the arm 62 into engagement with the links 37. On the shaft 65 is mounted an operating cam 68 which rotates with the shaft 65. The cam 68 engages the counter-weight 67 and may hold the selector arm 62entirely out of engagement with the connecting links 37.

In the operation of my device the ram 11 reciprocates in the ram box 12, being operated by any convenient mechanism (not shown). This drives the operating lever 19 through the link 18. When it is desired that the secondary ram have no motion, the Shaft 65 is rotated .clockwise, forcing the operating cam 68 against the counter-weight 67, thus moving the selector arm 62 entirely out of engagement with the connecting links 37. Should the secondary ram 26 be in any other position than its extreme forward one, the pin 61 willcarry the. connecting links 37 forward until the secondary ram reaches its extreme forward position. After this position of the secondary ram has been reached the pin 61 travels along the surfaces 54 and 53 but does not impart any motion to the rod 23. Should-it be desired to impart motion to the secondary ram 26, the shaft 65 is rotated counter-clockwise retracting the operating cam 68. from the counter-weight 67. This allows the counter-weight to pull the selector arm 62 rearwardly if-the operating arm 19- should be in its forward position.

Should the operating arm be in its rearward position and the ends 47 of the links accordingly raised through the action of the counter-weights 46, the links 37 prevent the as the operating arm 19moves forwardly, the pin 61 acting on the surfaces 54 depresses the ends 47 of the connecting links, thus permitting the counter-weight 67 to move the selector arm 62 in a counter-clockwise direction. The amount of rotation of the shaft 65 should be suflicient to cause the chamfered portions 58 of the links to engage one of the steps 63 of the selector arm, although no difliculties will follow if the movement is not exactly right. When the links 37 are held by the selector arm 62, the counterweights 46 are unable to raise the ends 47 and the pin 61 moves rearwardly away from the inclined surface 54. The pin 61 according ly engages one of the under-cut stepped portions 56 and the connecting links are forced rearwardl by an amount depending upon which un ercut portionis engaged. It is evident that the greatest motion of the secondary ram occurs when the chamfered surface 58 engages the lowest notch 63 on the selector arm 62. The relation of the parts of the apparatus is such that when the shaft 65 is rotated so as to permit the counterweight 67 to tip the arm of the selector 62 rearwardly toward the furnace the full amount possible, the lowermost notch 63 comes directly over the chamfered portions 58 of the links 37 when they are in their forwardmost position. Then as the main stoker ram 11 starts its rearward travel taking with it the upper end of the lever 19 and the pin 61, the notch 63.0f the selector 62 prevents the upward swing of the ends 47 of the links 37 by reason of the counter-weights 46. The pin 61 therefore is moved rearwardly until it engages the upper notch 55 of the link 37 and carries the link 37 and the secondary ram 26 rearwardly its full stroke. In this movement the undercut portion 56 of the upper nicitch 55 prevents the pin 61 from slipping o If the shaft 65 should. be rotated so that the cam 68 moves the arm of the selector 62 away from the links 37, for example to median position, then when the links 37 have completed their forward motion and the pin 61 is again being moved rearwardly, the

counter-weights 46 cause the ends 47 of the links 37 to tilt upwardly until they engage in the middle notch of the selector 62. The links 37 are then held in that position until the pin 61 is moved into engagement with the second notch 55 of the links 37, moving said links andthe secondary ram 26 rearwardly a shorter stroke than previously described.

It will be seen' that in my device the shaft 65 may be rotated at any phase of the cycle of operation. This is especially important in a multiple retort stoker as a single shaft 65 would normally operate a plurality of operating cams 68, there being one cam for each retort. If the rams of the several retorts operate in sequence it is evident that a device which could only be operated at a certain time would not be satisfactory for a multiple retort stoker.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications, without departing from the spirit thereof, and I desire, therefore, that till only such limitations shall be placed there upon as are imposed by the prior art or as are specifically set forth in the appended claims. a

What I claim is: 1. A mechanical movement comprising an operating arm, a connecting link, means on the operating arm for engaging the connecting link, said connecting link having a plurality of notches for'receiving the engaging means, means biasing the connecting link so that its notches tend to be out of engagement with the engaging means and means for positively holding said link during at least a portion of the stroke so that the operating arm engages one of the notches.

2. In an underfeed stoker having a main rain and at least one secondary ram, a secondary ram driving means comprising an operating arm driven by the main ram, a connecting link operatively connected to the secondary ram, said connecting link being provided with a plurality of notches, means on the operating arm for engaging a selected one of said notches, means normally biasing said connecting link out of engagementwith said operating arm, and adjustable means opposing said biasing means during at least a portion of the stroke to permit said means on the operating arm to engage a selected one of said notches.

3. In a mechanical stoker, a ram, a ram operating member, means for reciprocating the ram operating member, a variable stroke connection between said member and said means comprising a connecting link pivotally secured to the ram operating member and having a slot therein, said slot being provided on its upper side with at least two stepped notches, a pin operatively associated with said reciprocating means for engagement with the slot, means biasing the connecting link in one direction out of engagement with said pin, and means for positively holding the connecting link in any one of-a pluralit of positions, whereby any selected notch o the slot may be positioned to engage the pin of the reciprocatlng means.

4. In a mechanical movement a driven member, a driving member, a variable stroke connection between said driving and driven members comprising a connecting link pivotally secured to the driven member and having a slottherein, *said slot having a plurality of stepped notches in one side thereof, a pin operatively associated with said driving means for engagement with said slot,'1neans biasing said connecting link in a direction such as to cause the unnotched side of said slot to engage said pin, and means for holding said link during at least a part of the stroke in a selected one of a plurality of positions whereby any one of the several notches may be positioned to engage the pin.

5. In a mechanical movement a driven member, a driving member, a variable stroke connection between said driving and driven members comprising a connecting link pivotally secured to the driven memberand having a slot therein, said slot having a plurality of stepped notches in one side thereof, a pin operatively associated with said driving means for engagement with said slot, means biasing said connecting link in a direction such as to cause the unnotched side of said slot to engage said pin, and means holding said link during at least a part of the stroke in a selected one of a plurality of positions whereby any one of the several notches may be positioned to engage the pin, and means for changing the position of said holding means.

In testimony whereof, I have hereunto subscribed my name this twentieth day of November 1924. i

ANTHONY F. SCHWENDNER. 

